Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Based Compensation Expense

The following table discloses the amount of stock-based compensation expense for the three- and six-month periods ended June 30, 2016 and 2015:

	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
Stock options	$	27	$	2,323	$	458	$	3,378
Restricted stock units		1,946		1,888		3,769		3,082
Performance stock units		2,974		1,887		5,472		2,214
Total stock-based compensation	$	4,947	$	6,098	$	9,699	$	8,674

Details of Stock Options Activity

The following table provides details of the stock option activity for the six months ended June 30, 2016:

	Number of Shares
Outstanding at December 31, 2015		668,132
Exercised		(141,117	)
Expired		(1,596	)
Canceled		(4,398	)
Outstanding at June 30, 2016		521,021
Exercisable		406,794

Details of Nonvested Restricted Stock Units Activity

The following table provides details of the nonvested restricted stock unit activity for the six months ended June 30, 2016:

	Number of Restricted Stock Units
Nonvested at December 31, 2015		197,388
Granted		109,287
Vested		(34,981	)
Canceled		(1,487	)
Accrued dividend equivalents		1,771
Nonvested at June 30, 2016		271,978

Performance Based Units Earned under Long-Term Incentive Plan

The following table provides details of the nonvested performance stock units under the Company’s Long-Term Incentive Plan:

	Number of Performance Stock Units
Performance stock units outstanding at December 31, 2015		191,536
Granted		109,581
Canceled		(1,574	)
Accrued dividend equivalents		1,307
Performance stock units outstanding at June 30, 2016		300,850